Australia captain Ricky Ponting believes spinner Brad Hogg will play a key role when the champions take on South Africa in Wednesday's World Cup semi-final in St Lucia.

Left-arm wrist-spinner Hogg took four for 29 as Australia thrashed fellow last four side New Zealand by a massive 215 runs in the trans-Tasman rivals' final Super Eights match.

Only Australia fast bowler Glenn McGrath (22) has taken more than Hogg's 19 wickets at this World Cup.

And having already defeated South Africa by 83 runs in a group match last month, Ponting was confident former postman Hogg, and the likes of part-time spinners Michael Clarke and Andrew Symonds, could help deliver another victory against the Proteas, known for a weakness against slow bowling.

"South Africa probably won't play a spinner in their side. Those conditions and the way our spin bowlers are going, probably give us a bit of an edge," Ponting said.

Meanwhile, Ponting added that New Zealand were fooling no-one but themselves in their attempts to downplay the impact of Friday's defeat.

Kiwis skipper Stephen Fleming tried to minimise the impact of the largest reverse ever inflicted upon a Test nation at the World Cup, saying the Black Caps would just "wipe it off" ahead of a possible final meeting with the double-defending champions in Barbados on April 28.

"I'd rather be in our dressing room than theirs," said Ponting after a win which topped England's 202-run victory against India at Lord's in the inaugural 1975 World Cup.

"I'm sure they will be having all sorts of meetings over the next few days to talk about today's game.

"If they don't think that's going to affect them at all, then how is any psychological edge ever gained in any game of cricket? If we don't take something out of today's game, nobody ever can.

"We've just beaten New Zealand by 215 runs in a World Cup game, so they've got a lot of thinking to do."

Friday's win also ended a run of three straight defeats against the Black Caps when an under-strength Australia side were whitewashed 3-0 in February's Chappell-Hadlee Trophy in New Zealand.

Australia's imposing total of 348 for six, against a New Zealand attack missing sidelined pace bowlers Shane Bond and Jacob Oram, was built around Matthew Hayden's 103, the left-handed opener's third century of the tournament equalling the record for the most hundreds at a single World Cup.

With Ponting (66) he shared a second-wicket stand of 137 before Shane Watson, returning after three matches out with a calf muscle injury, stopped a nascent New Zealand recovery in its tracks with a blistering 65 not out featuring four sixes and four fours.

"We knew they'd have a weakened attack going into the game. We knew if we kept our partnership going we'd get a lot of bad balls," Ponting explained.

"Our batting has been excellent and it's getting better at the crucial part of this tour. It's a really exciting time and one all the guys in the Australian dressing room are looking forward to."

New Zealand, yet to win the World Cup, play 1996 champions Sri Lanka in Tuesday's first semi-final in Jamaica.